Inelastic lifetimes of hot electrons in real metals

TL;DR

This paper presents a first-principles GW-based calculation of inelastic electron lifetimes in copper and aluminum, revealing the influence of band structure, electron localization, and screening effects on these lifetimes.

Contribution

It provides a detailed, ab initio analysis of electron lifetimes in real metals, highlighting the roles of $d$-electrons and band structure in lifetime variations.

Findings

Copper lifetimes are larger due to $d$-electron screening.

Aluminum lifetimes are smaller due to band splitting.

Lifetimes result from a balance of localization, density of states, screening, and Fermi-surface topology.

Abstract

We report a first-principles description of inelastic lifetimes of excited electrons in real Cu and Al, which we compute, within the GW approximation of many-body theory, from the knowledge of the self-energy of the excited quasiparticle. Our full band-structure calculations indicate that actual lifetimes are the result of a delicate balance between localization, density of states, screening, and Fermi-surface topology. A major contribution from $d$-electrons participating in the screening of electron-electron interactions yields lifetimes of excited electrons in copper that are larger than those of electrons in a free-electron gas with the electron density equal to that of valence ($4s^1$) electrons. In aluminum, a simple metal with no $d$-bands, splitting of the band structure over the Fermi level results in electron lifetimes that are smaller than those of electrons in a free-electron gas.